Intracellular K+ activities and cell membrane potentials in a K+-transporting epithelium,the midgut of tobacco hornoworm (Manduca sexta)

Summary Transbasal electrical potential (V _b) and intraepithelial potassium chemical activity ((K⁺) _i ) were measured in isolated midgut epithelium of tobacco hornworm (Manduca sexta) using double-barrelled glass microelectrodes. Values ofV _b ranging from +8 to –48 mV (relative to blood side) were recorded. For all sites, (K⁺) _i is within a few millivolts of electrochemical equilibrium with the blood side bathing solution. Sites more negative than –20 mV show relatively high sensitivity ofV _b to changes in blood side K⁺ concentration: 43% of these sites can be marked successfully with iontophoresed Lucifer yellow CH dye and shown to represent epithelial cells of all three types present in the midgut. In about half of successful marks, dye-coupling of several adjacent cells is seen. Low potential sites — those withV _b less negative than –20 mV —typically do not show high sensitivity ofVb to changes of external K⁺, but rather (K⁺) _i rapidly approaches the K⁺ activity of blood side bathing solution. These sites can seldom be marked with Lucifer yellow (4% success). The mean (K⁺) _i of the high potential sites is 95±29 (sd)mm under standard conditions, a value which is in accord with published values for the whole tissue.     

Retinal mosaics of a primitive jumping spider,Spartaeus (Salticidae: Araneae): A transition between principal retinae serving low and high spatial acuities

Summary Previous papers (Blest andPrice 1984,Blest andSigmund 1984) have described the receptor mosaics in the tiered principal retinae of jumping spiders with high and low visual acuities, respectively. The latter paper offers a phylogenetic model for the later stages in the evolution of high acuity retinae in which layer I, farthest from the dioptrics, is alone required to sustain fine visual discriminations. Nevertheless, current evidence does not establish that the low acuity principal retinae of primitive jumping spiders were modified to yield the high acuity retinae of advanced forms: each might have evolved independently from a common precursor.We now show that the principal retina ofSpartaeus (the type genus of a primitive subfamily, theSpartaeinae) is a true intermediate between the low acuity retina ofYaginumanis and the high acuity retina ofPortia (also in theSpartaeinae).InSpartaeus, foveal layer I receptors at the anatomical outer side of the retina each bear a single rhabdomere designed as a light guide. Inner layer I receptors each have two rhabdomeres, and rhabdomeres of horizontally adjacent receptors are contiguous, so that optical pooling limits their acuity. Horizontal staircasing of the tips of layer I receptors was shown byBlest et al. (1981) to cause outer receptors to receive focused images from remote planes in object space, and inner receptors from nearer planes. In the high-acuity retina ofPortia all foveal layer I receptors are light-guides, and in the low-acuity retina ofYaginumanis none are. Layer I inSpartaeus, therefore, is a true intermediate step in the evolution of a high-acuity retina, and the local region of the foveal layer I mosaic modified to that end is concerned, appropriately, with the resolution of distant objects.The layer II mosaic is degraded, although less so than inPortia. Layer III is conservative throughout theSalticidae. Foveal layer IV exhibits greater homogeneity inSpartaeus than in other forms.     

New observations onPorphyridium griseum Geitler =Rhodella grisea (Geitler) comb. nova (Porphyridiales,Rhodophyceae)

The rare unicellular rhodophytePorphyridium griseum has been collected and isolated from basins, fed with thermal water, in Piestany, Czechoslovakia. This is the first report ofP. griseum sinceGeitler's find in the Neusiedler See, Austria. Ultrastructural investigations of the new strain demonstrate thatP. griseum belongs to the closely related genusRhodella. Comparison with current species ofRhodella and pigment analyses show thatP. griseum is identical to the marineR. reticulata and a new combination,Rhodella grisea (Geitler) comb. nov., is proposed to include both organisms.Dedicated to Prof. DrLothar Geitler on the occasion of his 90th birthday.     

Proline production via the arginine biosynthetic pathway: transfer of regulatory mutations of arginine biosynthesis into a proline-producing strain ofSerratia marcescens

Summary Proline production via a part of the arginine biosynthetic pathway was examined. About 20 mg/ml ofl-proline was produced by using arginine biosynthetic enzymes. Accordingly, three mutations of arginine biosynthesis, namely, derepression of arginine biosynthetic enzymes (assigned byargR2), feedback inhibition-resistant N-acetylglutamate synthase (assigned byargA2) and defectiveness in N-acetylornithine aminotransferase (assigned byargD ^–) were introduced by three transductional crosses into a proline-producing strain which produced about 55 mg/ml ofl-proline. The constructed strain produced 62 mg/ml ofl-proline, although about 10 mg/ml ofl-arginine and 1 mg/ml of N-acetylglutamate--semialdehyde were produced as by-products.     

Influence of photoperiod,temperature and host plant on the production of diapause eggs inPetrobia (Tetranychina) harti (Acari: Tetranychidae)

Petrobia harti (Ewing) diapauses in the egg stage. Adult females lay either diapause or nondiapause eggs. On the University of Thessaloniki campus (41°N), the mite was found to develop on leaves ofOxalis corniculata L. throughout the year, while no mites were found on leaves ofOxalis articulata Savigny growing in the same area. In the laboratory the mite could be maintained equally well on detached leaves of both plant species, kept on wet cotton-wool.Forty to 90% females laying diapause eggs (dlf) were produced when the mites developed under LD 1212 and 19±1 °C, or LD 168 and 19±1 °C or 25±1 °C on leaves ofO. articulata detached from plants grown in the open in various seasons. Under the same conditions, a very low to zero percentage ofdlf was produced onO. corniculata. By rearing certain feeding stages on one of these twoOxalis hosts, and the other feeding stages on the other host, various percentages ofdlf were obtained. These percentages were the net effect of the antagonistic action of the twoOxalis species.By rearing the mites at LD 8.515.5, LD 1212 or LD 168 and a temperature of 19±1 °C onO. articulata leaves renewed every 3 days, or every 16–18 days, or not at all, it could be shown that diapause induction or aversion is caused by the direct effect of photoperiod on the mites, and not by an effect through the host leaves.When wholeO. articulata plants were grown under LD 168 and 19±1 °C in the laboratory, or developed in the open during April and May, flowers were produced, while under LD 1212 no flowering occurred. In the laboratory under diapause-inducing conditions, higher percentages ofdlf were produced on leaves detached from flowering plants than on leaves detached from plants not flowering.OnO. articulata leaves at 20 °C, photoperiods with photophases equal to or longer than 12 h induced from 70 to 80%dlf, while photoperiods with photophases equal to or shorter than 10.9 h induced very low to zero percentages. By transferring different chrysalis stages from a diapause-inducing (LD 1212) to a diapause-averting (LD 8.515.5) photoperiod, and vice versa, it was found that the nymphochrysalis through deutonymph stages were sensitive to photoperiod, the deutochrysalis and deutonymph being the most sensitive.Under an LD 1212 photoperiod, a temperature of 20 °C induced diapause, whereas 25 °C, 30 °C, or a daynight thermoperiod of 25 °C18 °C suppressed it.     

Die Gattungsmerkmale vonSchizoboea (Gesneriaceae-Didymocarpeae)

The two characters used byBurtt (1974) to segregate the genusSchizoboea fromDidymocarpus, viz. terminal inflorescence and fruit splitting into 4 valves, have been studied in detail: (a) The terminal inflorescence represents a bracteate florescence (sensuTroll), that is an open thyrse, peculiar because of its only two extremely condensed internodes (basic internode + 1 following internode). Correspondingly, there are only two pairs of bracts from which the lower one only is capable to develop axillary partial florescences, i.e. pair-flowered cymes. Thus, the number of cymes is restricted to 2. Because of the condensed internodes, the inconspicuous bracts, and the densely aggregated flowers the two cymes simulate a unitary, terminal structure. By sympodial (± asymmetrically dichasial) linkage of shoot units, composed of an extended internode, a foliage leaf pair (from the axils of which the consecutive units arise) and the florescence,Schizoboea forms (polytelic) anthocladial shoot systems like some genera of the tribeKlugieae (incl.Loxonieae). (b) The fruit dehisces first loculicidally, then each valve splits into three portions (lateral rib and 2 semivalves). Moreover, the 4 placentae become isolated, thus the old fruit comprises 10 elements forming a loose fascicle.—The segregation ofSchizoboea fromDidymocarpus is supported. Whether the affinity is closer toSaintpaulia (as suspected byBurtt) ot toDidymocarpus, remains undecided: In regard to its shoot and inflorescence organization a morphological derivation is possible from both genera.

     

The pigments of Sphaerobolus stellatus (Tode) Pers

Petroleum ether extracts of discharged glebal masses and of developing fruitbodies ofSphaerobolus stellatus (Tode)Pers. were made and their absorption spectra determined. The residues from the extracts after evaporation were chromatographed. At least two colored fractions were discernible from the residue of the glebal masses; furthermore, at least three fractions (one of which is identical with -carotene) were distinguishable in the residue from developing fruit-bodies.     

Pistacia lentiscus cv. Chia (Anacardiaceae) on Chios island

The author discusses the history of an unusual form ofPistacia lentiscus L. (referred to as var.chia (Desf. exPoiret) DC. on the basis of literature data and personal field observations on Chios island. As a result of incisions made on the trunk and stems the tree exudes a specific resinous gum called mastic. The production of mastic currently amounts to 160–170 tons per annum and plays an important role in the economy of the island constituting the main source of income for approx. 20 villages in the south of Chios. The history of mastic dates back 2500 years to the time ofHerodotus. The author points out that on the plantation only male individuals are cultivated; these have been selected over a long period based on mastic yield. As they represent a group of cultivated clones it would be preferable to consider them as a collective cultivar Chia.     

The pollination biology ofHibbertia stricta (Dilleniaceae)

The exines of pollen grains ofHibbertia stricta (DC.)R. Br. exF. Muell. (Sect.Pleurandra) wear an oily, yellow pollen coat that stains positively for lipids. The pollen is collected by asocial bees, exclusively. The most common floral foragers are members of the genusLasioglossum (subgenusChilalictus;Halictidae) and they harvest pollen via thoracic vibration. As these bees cling to the inflated anthers their pollen smeared bodies come in contact with either of the two wet, nonpapillate stigmas. The stigmas respond positively to cytochemical tests for the presence of esterase immediately following expansion of the corolla, indicating the effective pollination period. The foraging patterns of the bees are narrowly to broadly polylectic. AsH. stricta flowers are nectarless, it is not surprising that bees bearing mixed pollen loads always carry the pollen of at least one nectariferous, coblooming plant. The pollination biology ofH. stricta is compared with otherHibbertia spp. and with pollen flowers in general.     

Isozyme evidence and the origin ofSenecio vulgaris (Compositae)

An electrophoretic survey of isozyme variation was conducted to test the hypothesis thatSenecio vulgaris L. (2n = 40) is of autotetraploid origin fromS. vernalis Waldst. & Kit. (2n = 20). It was established thatS. vulgaris exhibited fixed heterozygosity at three loci examined, showed disomic inheritance at all polymorphic loci, and contained a gene (Est-1) and an allele (Aat-3b) which were not present in the single population ofS. vernalis surveyed. From this it is concluded thatS. vulgaris is not of autotetraploid origin. Instead, the genetic evidence is in keeping with an allopolyploid origin ofS. vulgaris with the possibility thatS. vernalis acted as one of its two parents.     

Endogenous elemental sulfur production froml-cysteine in dormant α-spores ofPhomopsis viticola

The enzymatic production of sulfur froml-cysteine was studied in young dormant -spores ofPhomopsis viticola. Cysteine aminotransferase (CAT) and mercaptopyruvate sulfurtransferase (MST) activities could be responsible for the production of endogenous elemental sulfur (S⁰) in -spores.l-Cysteine was first deaminated, with production of -mercaptopyruvate, by the CAT. The -mercaptopyruvate produced is successively desulfurated by the MST with production of sulfur and pyruvate. Deaminase activity was recovered principally in the cytoplasmic fraction, whereas desulfurase activity was recovered mainly in the mitochondrial fraction.l-Cysteine and S⁰ sharply affected the respiratory activity, the ATP content, and suppressed germination of -spores. In contrast, reduced glutathione did not affect these metabolic parameters. Production of S⁰ by enzymatic degradation ofl-cysteine could be responsible for the inhibitory action of this amino acid. We suggest that CAT and MST, by their capacity to produce sulfur or S⁰, plays a key role in regulation of morphogenetic processes ofPhomopsis viticola.     

Aurantiosporium,a new genus forUstilago subnitens (Ustilaginales)

A new genus,Aurantiosporium Piepenbring, Vánky & Oberwinkler (Ustilaginales), is proposed for the smut speciesUstilago subnitens Schröter & Hennings onScleria melaleuca Reichb. The soral morphology, teliospore development, the ultrastructure of the teliospore wall and teliospore germination ofAurantiosporium subnitens, studied on collections from Costa Rica, are described for the first time. The character set ofA. subnitens including intercellular teliospore development, spores in irregular groups and light coloured spore walls with numerous layers in TEM is neither known fromUstilago norCintractia nor any other smut species.Part 113 in the series Studies inHeterobasidiomycetes from the Botanical Institute, University of Tübingen.     

Revision der GattungLoxonia (Gesneriaceae)

Within the genusLoxonia Jack, currently regarded as monotypic, three species are recognized:L. hirsuta Jack (Sumatra, Mentawai-Islands, Java, Borneo, Anambas-Islands, Malay Peninsula),L. discolor Jack (Sumatra) andL. burttiana A. Weber, spec. nova (Borneo). [Key with English translation p. 203.] There is evidence thatL. discolor is the most primitive species within the genus, the two others being derived from it.

Teil V der Beiträge zur Morphologie und Systematik derKlugieae undLoxonieae (Gesneriaceae).     

Presence of a sodium-dependentd-glucose transport system in the kidney of the atlantic hagfish (Myxine glutinosa)

Summary A membrane fraction, rich in brushborder membranes, was prepared from the archinephric duct of the atlantic hagfish (Myxine glutinosa) and the uptake ofd-glucose and other sugars into the membrane vesicles was investigated by a rapid filtration technique. Uptake ofd-glucose was found to be sodium-dependent, phloridzin-inhibitable and osmotically sensitive. A sodium gradient dependent overshoot was demonstrated at 25° C as well as at the more physiological temperature of 4°C. The sodium dependentd-glucose transport was inhibited by -methyl-d-glucoside, but not by 2-deoxy-d-glucose. Furthermore at the same concentration of sugars the initial uptake ofd-glucose was 7.2-fold higher thanl-glucose uptake.d-glucose transport across the membrane in the presence of a sodium gradient was stimulated when SCN^– replaced Cl^– and inhibited when gluconate replaced Cl^–.d-glucose uptake in the presence of a sodium- and potassium gradient was decreased by the addition of valinomycin. In addition, the presence of ad-glucose gradient enhanced sodium uptake into the vesicles as compared to a mannitolgradient. Phloridzin inhibited thed-glucose dependent sodium flux. Thus an electrogenic stereospecific sodium glucose co-transport system, with properties similar to that found in the kidney of higher vertebrates is present in this primitive vertebrate and might participate in secondary-active sugar reabsorption in the archinephric duct.     

Observations on Phyllachora aravalliensis Dakshini et al. Affecting oropetium thomaceum (Linn.) Trin.

The paper presents results of observations on the type material ofPhyllachora aravalliensis Dakshini et al. (Ph. aravalliense original) affectingOropetium thomaceum (Linn.)Trin. Three distinct types of spore bodies were observed in addition to the normal perithecia. These are spermogonia, microconidial locules and sterile perithecia with beaded filaments, reminiscent of asci, and constitute addition to the original diagnostic characters of the species ofPhyllachora.     

Effect of mercury vapour on the non-protein thiol content and respiration rate of eggs of the cattle tickBoophilus microplus (Acari: Ixodiae)

With continuous and ultimately lethal exposure of eggs ofboophilus microplus to mercury vapour, respiration and non-protein thiol decreased to low levels. With sub-lethal exposure, respiration decreased initially and then increased, whereas non-protein thiol (largely glutathione) increased initially and then decreased. This initial increase in glutathione (GSH) which probably resulted from an attempt by the organism to control or reverse the biochemical lesion, did not arise from the oxidized form (gssg) through a shift in the equilibrium from right to left thus: 2gshgssg+2H⁺+2e^–.The significance of the results are discussed in relation to theories ofgsh function and of Hg toxicity. The possible application of mercurials in tick control is discussed.     

Enzymic synthesis of the trisaccharide core region of the carbohydrate chain ofN-glycoprotein

Transmannosylation from mannotriose (Man1-4Man1-4Man) to the 4-position at the nonreducing end N-acetylglucosaminyl residue ofN,N-diacetylchitobiose was regioselectively induced through the use of -d-mannanase fromAspergillus niger. The enzyme formed the trisaccharide Man1-4GlcNAc1-4GlcNAc (3.7% of the enzyme-catalysed net decrease ofN,N-diacetylchitobiose) from mannotriose as a donor andN,N-diacetylchitobiose as an acceptor. Mannobiose (Man1-4Man) was also shown to be useful as a donor substrate for the desired trisaccharide synthesis.Abbreviations Man d-mannose - (M _n) (n=1–5) -linkedn-mer of mannose - GlcNAc₂ 2-acetamido-2-deoxy--d-glucopyranosyl-(1–4)-2-acetamido-2-deoxy-d-glucose     

Sexual compatibility between serotypes ofFilobasidiella neoformans (Cryptococcus neoformans)

Twenty-five of 37Cryptococcus neoformans strains of known serotype produced the basidiomycetousFilobasidiella state either alone or when paired with a strain of compatible mating-type. Sixteen strains were mating-type, four strains were a mating-type, and five strains were self-fertile.F. neoformans serotypes A and D were interfertile with compatible mating-types ofF. bacillispora serotypes B and C.C. neoformans var.gattii was interfertile with compatible mating-types ofF. neoformans andF. bacillispora. F. bacillispora strains, which utilized creatinine andl-malic acid, were interfertile with compatible mating-types ofF. neoformans, which did not utilize creatinine andl-malic acid. The interfertility between serotypes and biotypes eliminates the need for recognizing the names ofC. neoformans var.gattii, C. bacillisporus, andF. bacillispora. It is proposed thatC. neoformans var.gattii andC. bacillisporus be regarded as later, facultative synonyms ofC. neoformans and thatF. bacillispora be regarded as a later, facultative synonym ofF. neoformans.     

Die Verteilung der leitenden Strukturen in der Achse vonClematis vitalba (Ranunculaceae)

The vascular pattern and its origin are described in connection with the differentiation of ground tissue in the shoot. Leaf arrangement ofClematis vitalba L. is decussate, and the vascular pattern appears rather simple at first: From internode to internode six strands—three from each leaf—alternate. About six internodes from the shoot apex, the pattern is completed by accessory strands which do not leave the axis and differentiate near the primary bark and exactly between the old strands. The formation of the acessory strands is not caused by the enlargement of the axis alone, because the balance between ground and vascular tissue is already regulated by the enlargement of the primary strands.

Zweiter Beitrag der Serie Die Sproßentwicklung vonClematis vitalba (Ranunculaceae) vgl. den ersten Beitrag:Schnettker (1976).     

Genetics of a tissue esterase polymorphism (Est-6) in the rabbit (Oryctolagus cuniculus)

Genetic analysis of a polymorphic tissue esterase revealed a new locus (Est-6) with two alleles (Est-6 ^a andEst-6 ^b) on linkage group VI of the rabbit.Est-6 is closely linked to theEst-1,2,4 cluster. Esterase ofEst-6 is found in many organs, particularly in liver and small intestine, but not in erythrocytes and serum.Est-6 esterase hydrolyzes -naphthyl acetate and butyrate, naphthol AS-D acetate, indoxyl acetate, and butyrate as well as 5-bromoindoxyl acetate,N-acetyl-l-alanine--naphthyl ester but not 4-methylumbelliferyl acetate and fluorescein diacetate. The enzyme is inhibited by bis-p-nitrophenyl phosphate and eserine but not byp-chloromercuribenzoate. It was classified as a carboxylesterase (EC 3.1.1.1). Based on chromosomal localization, tissue distribution, substrate specificity, inhibitor sensitivity, and range ofpI's, rabbitEst-6 is assumed to be homologous with mouseEs-7.The contribution of Dr. O. von Deimling (No. 59) was supported by the Deutsche Forschungsgemeinschaft (De 315/2-2).